Thermostat-powered propulsion unit for toy vehicles



May 23, 1961 K. L. BELL THERMOSTAT-POWERED PROPULSION UNIT FOR TOYVEHICLES Filed June 5, 1957 2/ INVENTOR 6 KEITH L BELL i" 22 f BY "wATTORN Y United States Patent filice 2,984,974 Patented May 23, 1961THERMOSTAT-POWERED PROPULSION UNIT FOR TOY VEHICLES Keith L. Bell, 32 113th St. NE, Washington, D.C.,

assignor 'of one-half to Eugene H. Purdy, Washington, D.C.

Filed June 5, 1957, Ser. No. 663,780

12 Claims. (Cl. 60-3556) This invention relates to a thermostat-poweredpropulsion unit for play toys and which is especially suitable for usewith aquatic play toys such as toy boats or floating figure toys.

More particularly the invention has for an object to provide apropulsion unit of the above character comprising a receptacle forcontaining a thermal medium, which may be either a cooling medium or aheating medium, and a thermostatic element of the snap type, such as abimetallic diaphragm composed of laminated materials having differentcoefiicients of expansion and contraction, the construction andarrangement being such that the thermostatic element is adapted toperiodically snap in one direction to establish contact, or approximatecontact, with the thermal medium and to alternately snap in the oppositedirection out of contact with the thermal medium to impart propulsivethrusts to the toy. In the case of aquatic toys these propulsive thrustsact against the water in which the toy is partially submerged to propelthe toy through the water.

Another object of the invention is to provide a thermostat propulsionunit of the above character which is capable of utilizing as the thermalmedium either a frozen solid, such as ice or Dry Ice (solidified carbondioxide) or, alternatively, a heat emitting chemical, such for exampleas any of the well-known compositions that are commonly used in heatingpads and that are adapted to be activated by contact with water.

Still another object of the invention is to provide an inexpensive playtoy having no complicated mechanical parts and which is completely safefor use by children.

Other objects and advantages will be apparent from the followingdetailed description of a preferred embodiment of the invention,reference being made to the accompanying drawnig, in which:

Figure 1 is a side view of a toy boat;

Figure 2 is a stem end view of the boat;

Figure 3 is a fragmentary longitudinal cross-sectional view of the sternof the boat showing the propulsion unit;

Figure 4 is a side view of a floating figure toy utilizing a propulsionunit representing another embodiment of the invention;

Figure 5 is a detailed perspective view of a thermal medium containerforming a part of the propulsion unit of Fig. 4; and

Figure 6 is a fragmentary longitudinal cross-sectional view of the outerend of the chamber and container for receiving the thermal medium.

The toy boat 1 illustrated in Fig. 1 may be of any suitable design andcomprises a hull made of plastic or other light-weight material.Extending medially along the bottom of the hull is a comparatively widekeel 2 molded integral with the hull and comprising side walls 2a and abottom wall 3. This keel defines a trough opening into the interior ofthe hull and is closed at its stern end by a vertical wall 4. The bottomwall 3 of the keel slopes forwardly and downwardly for a substantialportion of the length of the hull, as indicated at 3a, and thenceforwardly and upwardly, as indicated at 3b, toward the bow of the boat,the two angularly disposed bottom sections forming a catch-basin or sump3c in the trough for a purpose later to be explained.

A vertical partition 5 and a preforated bottom partition 5a bridge thetwo side walls 2a of the trough adjacent its stern end, these partitionsforming with the two side walls and the end wall 4 a square orrectangular-shaped chamber 6 of approximately the size of an ice cube(indicated at 7) of the kind that is frozen in ice trays of the usualhousehold refrigerators. The chamber 6 is of somewhat greater lengththan the ice cube so as to provide space for a coil spring 8 abutting atone end against the partition 5 and at its other end against a presserplate 9 adapted to contact the ice cube and urge it toward the end wall4. A cover 10 provided with a handle or knob 10a normally closes the topof the chamber 6 but is removable to allow the introduction of an icecube into the chamber. The inner walls of the chamber may be faced withwater-impervious paperboard or other heat-insulating material (notshown) to prevent too rapid melting of the ice cube. However, suchinsulation is not essential since the low heat-transfer characteristicof the plastic composing the material of the boat will usually besufficient to provide adequate insulation.

The end wall 4 of the chamber is provided with an opening 11 which isclosed by a flexible diaphragm 12 composed of two laminated materials12a and 121) having different coefficients of expansion and contractionso that when subjected to heat this diaphragm will snap in one directionand upon cooling will snap in the opposite direction. Such bimetallicthermostatic elements are well known per se in the mechanical andelectrical arts, being commonly used in blinker lighting circuits tomomentarily interrupt the electrical current to a lamp. While hereinreferred to generally as bimetallic elements, the laminated materialsmay be non-metals, for example plastics, which possess suitablydifferent coefiicients of expansion and contraction. The term bimetallicas used herein is therefore used broadly to include thermostatsemploying any two laminated materials having different thermalcoefiicients of expansion and contraction. The diaphragm is illustratedin the form of a button which is adapted to warp from the full lineposition to the dotted line position shown on an exaggerated scale inFig. 3. The end wall 4 of the chamber 6 is thickened surrounding theopening 11 as shown in Fig. 3 to provide an abutment against which theice cube is urged by the presser plate 9 in order to afford a clearancethrough which the button is free to snap into engagement, orsubstantially into engagement, with a surface of the ice cube in onedirection of flexing of the diaphragm.

The operation of the thermostat propulsion unit just described is asfollows: The cover 10 of the chamber 6 is removed and an ice cube 7 isinserted into the chamber between the presser plate 9 and the end wall4, after which the cover is restored and the boat is placed in a body ofwarm water. The submerged diaphragm being exposed to the heat of thewater will buckle inwardly to the position shown exaggerated in dottedlines in Fig. 3 due to the difference in expansion of the laminatedmaterials composing the diaphragm. This causes the diaphragm to contacta surface of the ice cube which rapidly abstracts heat from thediaphragm and causes the diaphragm to buckle outwardly in the oppositedirection. The periodic contraction and expansion of the diaphragmoccurs quite rapidly, causing the diaphragm to buckle inwardly andoutwardly with a pulsating snap action so as to propel the boatforwardly through the water.

As the ice melts, the cube will be continuously urged into engagementwith the end wall 4 by the presser plate 9. The water melted from theice passes through the perforated bottom 5a of the chamber 6 and drainsdown the inclined bottom 3a of the trough to collect in the sump 30,located approximately midship, where its weight does not interfere withthe stability of the boat. The cold water resulting from the melted iceshould be prevented from coming into contact with the inner face of thediaphragm where it would interfere with the thermostatic operation ofthe diaphragm. When the ice cube has entirely melted, the boat may betaken from the water and overturned to drain therefrom the waterresulting from the melted ice, after which another ice cube may beinserted in the chamber 6. The boat is ideally suited as a childrensplay toy for the bath tub where the water is sufiiciently warm to causethe thermostatic motor to operate efficiently.

A modification of the invention is shown in Figs. 4, 5 and 6 applied toa floating figure toy. The figure toy 13, here illustrated in the formof a duck, may be made of any suitable material, for example plastic,being preferably hollow inside to render the figure light and buoyant inorder to float partially submerged in the water. Molded integral withthe body of the duck or attached thereto below the float line is arectangular shaped watertight chamber 14 open at its end opposite thedirection in which the duck is facing.

A rectangular-shaped ice container 15 having side, end and bottom wallsis adapted to contain an ice cube 16 as shown in Fig. 5. A coil spring17 is interposed between an end wall 18 of the container and the icecube so as to urge the cube against the opposite end wall 19 of thecontainer. The end wall 19 is composed of thin sheet material throughwhich heat is readily transmissible and, if desired, the entirecontainer may be made of thin sheet metal.

Secured to the outer face of the end wall 19 is a buttontype thermostat29 which may correspond in all essential respects to the thermostat 12heretofore described in connection with the toy boat of Figs. 1, 2 and3. The diaphragm 20 is marginally supported upon a rectangular spacerframe 21 which, in turn, is secured to the outer face of the end wall 19of the container whereby the diaphragm is free to flex into the dottedline position indicated, somewhat exaggerated, in Fig. 6, in whichposition the diaphragm contacts the end wall 19. The end wall 15* ispierced to provide breather apertures 2?. to allow flexing of thediaphragm. Bonded to and encircling the container 18 adjacent the endwall 19 is a rubber packing strip 23 adapted to seal the space betweenthe chamber 14 and container 15 to prevent the entrance of water intothe chamber when the duck is in the water. A spring latch 24 secured tothe bottom of the chamber is adapted to engage a margin of the outer endof the container to retain the container in the chamber.

he mode of operation of this embodiment of the invention is essentiallythe same as that described in connection with the toy boat of Figs. 1through 3. An ice cube, or a supply of chipped ice or Dry Ice, is placedin the container 15 and the container is inserted into the chamber 1d,.being retained therein by the latch 24. When the duck is placed in warmwater the thermostatic diaphragm will snap back-and-forth into and outof contact with the cold end wall 19 of the container 19 and thispulsating action will impel the duck forwardly through the water. Bylocating the diaphragm below and offside of its center of gravity, arocking or bobbing motion may be imparted to the duck as it movesthrough the water. T he water from the melting ice will collect in thecontainer and be maintained out of contact with the diaphragm.

While in the above embodiments of the invention the thermal medium forthe thermostatic propulsion unit has been described as an ice cube,manifestly any other frozen solid such as ice chips or Dry Ice may besubstituted as the cooling means. Such cooling medium is satisfactorywhen the toy is to be floated in Warm or hot water. However, in theevent the toy is to be used in cold water, a heating medium must besubstituted for the cooling medium in order to provide the necessarydiiferential in temperature to which the thermostat is exposed. Such aheating medium may comprise a composition, of which sodium acetate is anexample, in which heat is generated by introducing water into thechemical. Such compositions are well known in the heating pad art andreference is made to the patents of lost -No. 1,812,243 and Johnson No.1,481,208 as an example of such compositions. Such compositions areusually packaged in rubber, fabric or paper bags or packets and thesemay be made of a size approximately the size of an ice cube so as to fitwithin the chamber reserved for the thermal medium.

Manifestly various changes in construction, arrangement and design maybe made in the form of the'inventions described and illustrated hereinwithout departing from the spirit of the invention as defined by thefollowing claims.

I claim:

1. A propulsion means for floatable bodies comprising the combinationwith a floatable body having an outer surface a portion of which surfaceis adapted to lie in contact with the liquid in which the body isfloated, of a bimetallic thermostatic diaphragm of the snap-type formedof materials having diflerent thermal coeflicients of expansion, saiddiaphragm forming a portion of said surface and adapted to be exposedupon one of its faces to the pressure and temperature of the liquid andupon its other face to the pressure and temperature of-the air, andmeans for maintaining a temperature zone appreciably diflerent fromatmospheric temperature located in spaced relation to the air-exposedface of the disk but adapted to be intercepted by said face in oneposition of movement the snap diaphragm to alter the temperature of thediaphragm.

2. In a propulsion unit for toys, the combination of a container forcontaining a thermal medium, a flexible diaphragm of the bimetallic snaptype formed of materials having different thermal coeflicients ofexpansion, said diaphragm forming a portion of the wall of saidcontainer, and means for maintaining a thermal medium within saidcontainer a spaced distance from the diaphragm correspondingapproximately to the range of buckling movement of the diaphragm,whereby the diaphragm is adapted to buckle substantially into and out ofcontact with the thermal medium to intermittently impart a change oftemperature to the diaphragm.

3. A thermostat-powered propulsion unit for floating aquatic toyscomprising a chamber for containing a thermal medium, a flexiblediaphragm of the bimetallic snap type formed of materials havingdifferent thermal coeflicients of expansion, said diaphragm forming aportion of the wall of said chamber angularly inclined to the horizontaland disposed below the float line of said to, and means for supportingthe thermal medium a spaced distance from the diaphragm when thediaphragm is in its outward position of flexure, said spaced distancecorresponding approximately to the range of buckling movement of thediaphragm, whereby the diaphragm is adapted to buckle substantially intoand out of contact with the thermal medium to intermittently impart achange of temperature to the diaphragm.

4. A thermostat-powered propulsion unit for floating aquatic toyscomprising a chamber for containing a thermal medium, a flexiblediaphragm of the bimetallic snap type formed of materials havingdifferent thermal coefficients of expansion, said diaphragm forming aportion of the wall of said chamber angularly inclined to the horizontaland disposed below the float line of said toy, and means for supportingthe thermal medium a spaced distance from the diaphragm when thediaphragm is in its outward position of fleXure, said spaced distancecorresponding approximately to the range of buckling movement of thediaphragm, whereby the diaphragm is adapted to buckle substantially intoand out of contact with the thermal medium to intermittently impart achange of temperature to the diaphragm, and means resiliently urging thethermal medium towards said diaphragm.

5. A thermostat-powered propulsion unit for floating aquatic toys as setforth in claim 4 wherein the container has a wall of highlyheat-conductive material disposed opposite the diaphragm.

6. A thermostat-powered propulsion unit for floating aquatic toyscomprising a chamber for containing a cooling medium in solid form, aflexible diaphragm of the bimetallic snap type formed of materialshaving diiferent thermal coefficients of expansion, said diaphragmforming a portion of the wall of said chamber angularly inclined to thehorizontal and located below the float line of said toy, abutment meansfor maintaining the solidified cooling medium within the chamber aspaced distance from the diaphragm when the diaphragm is in its outwardposition of flexure, said spaced distance corresponding approximately tothe range of buckling movement of the diaphragm, whereby the diaphragmis adapted to buckle substantially into and out of contact with thecooling medium to intermittently impart a change of temperature to thediaphragm.

7. A thermostat-powered propulsion unit for floating aquatic toys as setforth in claim 6, including means for preventing liquid melted from saidcooling medium from contacting said diaphragm.

8. A thermostat-powered propulsion unit for floating aquatic toys as setforth in claim 6, including drainage means for directing liquid meltedfrom said cooling medium out of contact with said diaphragm.

9. A thermostat-powered propulsion unit for floating aquatic toys as setforth in claim 6, in which the bottom of the chamber is provided withdrainage openings, including a sump for collecting the liquid meltedfrom said cooling medium passing through said drainage openings.

10. A thermostat-powered propulsion unit for floating aquatic toyscomprising a chamber open at one end, a container for a thermal mediuminsertable into said chamber having a Wall of heat-conductive materialclosing the open end of said chamber, a flexible diaphragm of thebimetallic snap type formed of materials having different thermalcoeflicients of expansion, said diaphragm mounted upon thechamber-closing end of said container angularly inclined to thehorizontal and located below the float line of said toy, said diaphragmbeing supported in spaced relation to the heat-conductive wall of thecontainer in one position of flexure of said diaphragm and substantiallyin contact with the heat-conductive wall of the container in theopposite direction of flexure of said diaphragm, and releasable meansfor retaining said container in said chamber.

1 1. A thermostat-powered propulsion unit for floating aquatic toys asset forth in claim 10 in which the container is provided with enclosingbottom and side walls for confining the thermal medium within saidcontainer.

12. A thermostat-powered propulsion unit for floating aquatic toys asset forth in claim 10 in which the container is made of relatively thinsheet metal.

References Cited in the file of this patent UNITED STATES PATENTS118,151 Raynale Aug. 15, 1871 1,481,270 Purcell Jan. 22, 1924 1,993,670Jones et a1. Mar. 5, 1935 2,471,240 Rider May 24, 1949 2,572,162 KoonzOct. 23, 1951 2,681,656 Starkenberg June 22, 1954 2,687,005 IngersollAug. 24, 1954 2,881,558 Bell Apr. 14, 1959

